Ball bearing structure



Oct. 9, 1934. v. l.. SCOTT BALL BEARING STRUCTURE.

Filed June 16, 1930 IN VEN TOR l//Z/o/"L 56051?,

ATTORNEY Patented Oct. 9, 1934 f uNiTED STATES PATENT orifice;

1,976,637` y lBALI. BEARING STRUCTURE `Victor L. Scott, Ottumwa, Iowa l Application June 16,1930, serial No. 461,508 j claims. (o1. 30s- 261) The present invention has relation to ball bearing construction, and the primary object in View is to provide an improved type of ball bearing structure in which the arrangement and distribui tion of the ball elements is such as to divide the load as evenly and uniformly as possible over a considerable number of such elements, and with# out any appreciable deformationA of any of the ball elements or eitherbf the bearing surfaces engaged thereby.

Accordingly,- one of the features of Ythe present invention consists` in providing a ball bearing structure made up of a plurality of series of ball bearings, and arranged in such a way that no two 4of the ball bearings of the entire construction are allowed to travel in the same path about the axis of the bearing.

y A further object of the invention isto devise a bearing structure of this type in which direct provision is madeto allow for a certain degree of compensation for irregularities in the bearing elements, with a view to permitting the bearing assembly, in the breaking in operation, during the initial period of service of the bearing, to assume a permanent relation of the various elements in which the ball bearing surfaces receive a more nearly even distribution of the load, and without any injurious distortion or deformation of the bearing elements during this breaking in period'of the bearing.

In carrying out this'feature of the invention, I make use of inner and'outer bearing members or bushings of slightly different relative density, whereby the ball bearings are permittedto producev their ownl tracks'or grooves as they wear and seat themselves in the relatively softer bearing'surface', at'the same time producing av cold hardeningiaction along the surface thus'tracked, in thewear'ing-in process.

j t-is further sought, as a-partof my invention, t'oi'clevisevr an improved construction process, for the production vof ball bearings possessing my im-` proved'features, including the method of drilling the ball retainer member, in order that no two ballsof the same bearing shall travel in the same path around the axisyof the'` bearing, and also my method of providing for a bearing which willvbe more' nearly correct and 'accurate in its operation, in distributing the load, by designing the bearing assembly for'. an initial compensating action to allow theball elements to seat themselves in one of the bearing surfaces, as above referred to. I

With the'foregoing general objectin view, the invention will now be 'described by reference to 'the acoo'rnp'anyingV drawing illustratingone form of bearing construction which I have devised for embodying. the proposed improvements, after which the various features and combinations of the same deemed to be novel will be particularly set forth and claimed' Y' In the drawing- Y f Figure 1 is a plan view illustrating a portionV of a ball retainer member `drilledlrwith openings in accordance with the'practice of the present invention;

Figure 2 is an exterior view (partly broken away) of a drilling machine of the type for which the present bearing structure is particularly adapted; andY Figure 3 is an enlarged sectional detail, lrepre- 7.0. senting a section taken on the line 3-3 OfFigure 2, and also representing a cross-section of th'eb'all retainer member as indicated by the line 3a-'-3a ofFigure 1. Referring now to the drawing in detail, inthe practice of my invention I prepare the Vball retaining member by drilling a steel sheet'4 of appropriate size with a plurality of ball retaining openings 5 of the same exterior diameter as the balls 6 which are to be used in the bearing. These 8 0 openings or holes are drilled by the so-called index method, with the object of so arranging the holes that when the entire set has been drilled no two of them will be in the same alinement longitudinally of the sheet 4. Accordingly, the drilling of S5 the rst set of holes 5, indicated at A, is started as near to one side margin of the sheet 4 as is practicable, but with .each succeeding hole located progressively nearer to the opposite side of the sheet. The second-set of holes indicated at B, is startedfa'rther over on the sheet, being drilled intermediate the holes of the set A andlikewise has each succeeding hole drilled 'progres-Y sively nearer to the' 'opposite side; and so on with each succeeding series, a's'indicatedv at 95v C, D,'E, F, etc., thearrangement.orpattern and number of the openings beingv adapted, 'of course,v to the diameter and width of the particular bear. ingl involved, but always with the lsame final re-` sult in View, to produce a non-spiral relation of the bearing openings so that no two of the openl ings'5 shall be inthe same longitudinal aline-fment, and also an irregularly'staggeredrelation'of the openings with the. result that preferablynot more than two of them, in the construction illustrated, will fall in the same transversey alinement, after all-the openings have been drilled. For the bearing sleeves or bushings, a yfixed outern bearing member 7 is chosen whose bearing surface is ofya permanently glass-hardenedvchar- 11.0

fief' f service of the bearing structure, as it is .brvoken in, the balls 6 will seat themselves, producing their own separate and individual tracks or channels in'lthefsurface 4of the inner journal bearing member 8; as indicated Vby the referencernumeral 9 in Figure 1, and therefore in the nal bearing there will be as .many separate tracks or channels 9 as the total number of balls 6 in the complete bearing assembly, the remaining tracks coming intermediate the lines 9 represented on the' 'draw-' s. fixed bearing 7, in order to ycompensate for the ine. While intheory, ball bearing structures are constructed to evenly distribute thev loadabout the bearing, it is of course impossible tovyproducegabsolutely invariable. bearing elements," as balls of,.the.`most'accurate manufacture will always vary slightly, in size, shape,.density, etc. When placed in service, the balls and bearing surfaces in engagementtherewith will undergo momentary deformation at each passage ofthe load.A For each difference or irregularity in the bearing elements, therewill of coursebe a correspondingV strain upon theelements to which the greater stress is applied,fand-where the balls vary -in size, there will always be a greater strain imposed on the larger sized ball. In designing the bearing, it is essential that the size and extent of the bearing shall be suchthat any deformation occurring shall not be beyond the capacity of the balls. and bearing surfaces to withstand, otherwise the life of the (bearing will be vextremely short. A certain safety factor is always figured, to .compensate for any inaccuracies in material and workmanship, vso that the bearing is constructed with a safe margin of load carrying. capacity, that is, greater than 'the ltheoretical capacity of the bearing. l

It is apparent, that the more 'nearly it is possible to approximate a perfectly even distribution of the load throughout the series of the ball bearings/used, lthe necessity for the safety factor disappearsythe Wear in the bearing vis reduced Yto a practical mini-mum, and they life of the bearing indefinitely prolonged. Since it is` impossible to provide ballfbearings ofabsolutely uniformsize, itbecomes evident thattheremust be some compensa-tion for this difference inthe manufacture, if there yis to be any practicalnuniformity, in the operation of the'bearing structure. I have there-AV fore conceivedthe idea .ofymaking the initial period of .service of the bearing -bring about the necesi-, sary compensation for the .differences in the ybear- .ing elements; that ispthebreaking-in ofp'the bearing -jis'thereby causedtowear -in the. various parts 1of thebearingin suchal way as to eliminate the 'irregularities :referred to. 1 y. This lisprovided forin the improved bearing by making the inner or journal'bearing. member 8 of relatively rsofter density, in order that any excess pressure 'applied' tothe severaly ball bearings 6 will cause these` to wear in or seat themselvesjin the surfacefof the bearing member 8. Asma-,conf sequence, the ldeformation madeneces'sary byithe irregularities andV resultant excess load upon-,the corresponding bearing elements is caused to take place in the inner bearingmember 8, Vand in such airway that itheballsywithout change in themselves, manufacture .their own raceways or -zbearingfgrooves iin 'the surface'of the'b'earing member 8.' yThis .tisone 'vital improved featureof :ny-in'-4 vention...V m x f produces its own individualrraceway .or bearingA groove in the member 8, and thereafter tracks in this separate individual groove throughout the remaining period of operation of the bearing. The density of the inner bearing member 8 is not required to be greatly less than that of the outer irregularities in theballs 6 and permit these to seat themselves the-necessary extent, without any damage to either the balls or the surface of the outer bearing member 8; besides which, the continued cold rolling action ofthe bal1s,;6 -along their respective individual paths over the surface of the bearing member'S will produce theneces-.`

- sary hardeningaction ,to bring this bearing sur-- rface ,along .the, fpaths'of.the balls 6 ltofapproximately the same hardnessas that vof the balls themselves.v I

- ByV means of av bearing 4design andassembly this` character, it is apparent that the loadmaygbe distributedrover such a multiplicity of1ba-lls that the loaden-any one of vthem will be extremely small, and with each ball .traveling'inits vown individual raceway the wear. taking place inthe bearing is kepty so small-as to be almost negligble, thereby giving the bearing structure almost unlimited Wearing qualities. k l u..

The distribution of the load Amay be thusfspread evenly over abearing vof so great anextent as makes possible the use .of ball bearings `of so small a diameter as to Yrender the improved construction especially desirable and useful apparatus where the severe loadconditions demand aheayy duty bear-ingand at .the same time limit Athev size of the ,bear-ing .as 'regardsthe radius between the operating Ymemberorshaft* and the exterior of the bearing. This-is especially 'true -coa'ldri-ll ing apparatus -of rthe type shown-in 2, illustrating.the gear and motor casenlO-atrone side of whichismounted the h ousingportion 12 through which operates the ydrillbar laL 'for which a suitable` type of -ball bearing structure must-be provided. When it d.is considered thatlmany .of the positions in4 which a--drillingfLmacliinaof this character 'must be operated require-that the barmust-bemaintained almost directlyilush with theY face-of l:v3*. wall, floor or .ceiling.a.fo'rdingla minimum fof clearancebetween such'workingface and thefairis of the vdrillfb'ar,.the necessity of prof viding a bearing structure .small venoug' llft' i `be accommodated Within such spaceV andat the' same time affording Athe requisiteload carryingcapacity is clearly demonstrated. 1 It is howeverevident that the;.characteristics yof v the improvedfbearing .construction fulfill alltheserequirements; and will offer alpracticaland iefficient construction u.of unique--design-as regardsv thoseout standing@prop` k .orties above emphasized, :that :of-,automatically producing separateand,individualbearingggrooyes for each and every-ballfand [compensating -fnrthe intrinsic differences and peculiaritiesof the llea-me,-

invention, I desire to reserve the right to make all such changes or modifications as may fairly fall within the scope of the appended claims.

What I claim is:

1. A ball bearing structure comprising spaced inner and outer bearing members having opposed bearing surfaces, ball bearings interposed between said members for engagement with said surfaces,

one of said bearing surfaces being initially of relatively softer density for accommodating irregularities in said ball bearings, and ball-retaining means arranged to maintain the ball bearings in irregularly staggered and non-spiral relation with .no two of them the same circumferential alinement.

2. A ball bearing structure comprising spaced inner and outer bearing members having opposed bearing surfaces, ball bearings interposed between said members for engagement with said surfaces, and a ball retainer member acting to maintain said ball bearings in spaced relation both transversely and circumferentially of the bearing structure and also in groups staggered irregularly crosswise of the bearing structure, but with no two of the ball bearings in the same circumferential alinement.

3. A ball bearing structure comprising, a cylindrical ball retainer, and a plurality of ball bearings maintained by said member in non-spiral relation with no two of the ball bearings in the same circumferential alinement, and also in relatively and irregularly staggered positions for preventing progressive impelling of the lubricant in the direction of either end of the bearing structure. r

4. A ball bearing construction comprising, a plurality of ball bearings, and a cylindrical ball retainer member provided with ball 4retaining means engaging and holding the balls in relatively and irregularly staggered positions cooperating to prevent progressive impelling of the lubricant in the direction of either end of the bearing construction.

5. A ball bearing construction comprising, a plurality of ball bearings, and a cylindrical'v ball retainer member provided with separate ball engaging and retaining means arranged in staggered and non-spiral relation for holding the balls in relative positions cooperating to prevent progressive impelling of the lubricant in thedirection of either end of the bearing construction.

VICTOR L. SCOT'I'. 

